I'm having problems with bluetooth connection to a Mutant MT2200BT car 'head unit'.

I can listen to mp3 tracks from the E63 'Music Player' through the Mutant via A2DP. Problem is, if I interrupt the playback eg to make a call via bluetooth, playback ceases, and has to be restarted from the E63.

If I'm listening to mp3 tracks on the E63 via headphones and I make a call directly, playback pauses but resumes when the call ends.

Is there some setting I need to change, to stop the bluetooth link stopping 'Music Player'? Can't figure this one out!

I suspect the problem may lie with the Mutant, since it has other odd 'bluetooth' behaviour. The supplied manual is poor, so no clues there; I've put in a help request to the manufacturer, but not heard back yet.

However, I was just wondering whether it's a general bluetooth thing, it's a new technology to me. For example, can bluetooth support more than one 'channel' of data? Am I expecting too much for it to be able to stream mp3 files and carry phonecall data at the same time?

Also, A2DP is uni-directional, so does that mean that once the stream is interrupted, there's no way to start it from the destination again?

Generally only one channel at time... I said that because there is one brand, I don´t remember what is, but support to at time.
After that try test that with another kit or another phone with the same kit.